Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Physiology Essentials > Cardiovascular System > Flashcards

Cardiovascular System Flashcards

1
Q

What are functions of blood?

A

1) Transport of dissolved substances
2) Regulation of PH/Ions
3) Restriction of fluid losses at injury sites
4) Defence against toxins/pathogens
5) Stabilise body temperature
6) Maintains homeostasis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the components of blood?

A

55% Plasma
-Water, dissolved plasma proteins
-Materials exchanged across capillary walls
45% Formed Elements
-Red blood cells (transports oxygen)
-White blood cells (provide body defence)
-Platelets (cell fragments involved in clotting)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Describe the structure of red blood cells.

A
  • Biconcave disks, maintained by fibrous protein spectrin

- Provides flexibility

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the structural characteristics of red blood cells?

A
  • Hemoglobin carry oxygen from lungs to tissues
  • Large surface area to volume ratio= carry more oxygen
  • Don’t consume oxygen: lack mitochondria
  • Hematocrit: % of formed elements in blood sample
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is erythropoiesis?

A

Stem cells mature to become red blood cells, occurs in myeloid tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe regulation of red blood cells by EPO.

A

Controlled by negative feedback

  • low oxygen levels in blood (hypoxia)
  • kidney senses hypoxia and releases Renal Erythropoietin Factor (REF)
  • REF converts plasma protein to erythropoietin
  • Erythropoietin converts plasma protein to erythropoietin
  • Erythropoietin stimulates red bone marrow to produce more RBCs to carry more oxygen
  • Oxygen levels in blood return to normal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe process of clot retraction

A

1) Platelets contract
2) Pulls torn edges of vessel closer together
3) Fibroblasts form new connective tissue, endothelial cells repair vessels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the phases of hemostasis?

A

1) Vascular Phase
2) Platelet Phase
3) Coagulation Phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describe the vascular phase

A
  • Cut in blood vessel wall, smooth muscle contracts

- Endothelial cells contract and become sticky

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe the platelet phase

A
  • Begins within 15 seconds
  • Platelet plug formation: stick to endothelial surface
  • Platelets activated: extend projection and attach to each other
  • Platelets releases chemicals, promote aggregation/vascular spasm/vessel repair/clotting
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe the coagulation phase

A
  • Begins 30 seconds after injury
  • Blood clotting
  • Clotting factors promotes formation of prothrombinase
  • Converts prothrombin –> thrombin
  • Converts fibrinogen –> fibrin, makes blood clot
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe arteries/arterioles

A

Carry blood away from the heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe veins/venules

A

Carry blood to the heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe role of capillaries

A

Exchange of gases and nutrients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is a pulmonary circuit?

A

Carry blood to and from the lungs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is a systemic circuit?

A

Carry blood to and from the organs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe the structure of the heart?

A
  • Double walled sac of connective tissue
    1) Epicardium Wall (surrounding heart)
    2) Myocardium Wall (cardiac muscle)
    3) Endocardium Wall (simple squamous epithelium lining the heart)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Describe the internal structure of the heart

A
  • Atrioventricular valves (AV valves), right= tricuspid valve, left= bicuspid valve
  • 2 semilunar valves: pulmonary valve (lungs), aortic valve (aorta)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Describe blood flow through the heart

A 
(deoxygenated blood)
Superior/Inferior vena cava
Right Atrium
Tricuspid Valve
Right Ventricle
Pulmonary Valve
Pulmonary Trunk
Lungs
(oxygenated blood)
Left Atrium
Mitral Valve
Left Ventricle
Aortic Valve
Body Tissue
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Describe an electrocardiogram (ECG)

A
  • Assesses electrical event of conducting system
  • Depolarisation: initiates contraction of muscles
  • Repolarisation: initiates relaxation of muscles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the stages of the cardiac cycle?

A
  • Atrial Systole
  • Atrial Diastole
  • Ventricular Systole
  • Ventricular Diastole
22
Q

Describe atrial systole

A

-Atria contract, filling ventricles completely with blood

23
Q

Describe atrial diastole

A

-Atria relax

24
Q

Describe ventricular systole

A
  • Ventricles contract
  • Pushing blood out of AV valves into systemic and pulmonary circuits
  • Occurs at same time as atrial diastole
25
Q

Describe ventricular diastole

A
  • Ventricles relax

- Blood passively flows into atria and ventricles during this time

26
Q

What is the conducting system?

A
  • Initiating/distributing electrical impulses

- Each heart beat begins with an action potential

27
Q

Describe the conducting system process

A

1) Action potential initiates contraction
- Pacemaker cells depolarise and initiate impulse
2) Filling up lower chambers
- Depolarisation wave travels via internodal pathway to atria
- Stimulus travels to AV node
- Resister node enables time for atria to contract and fill lower ventricles
3) Ventricle contract
- Stimulus travels from AV node –> AV bundle
4) Stimulus passes through left and right bundle branches
5) Stimulus travels to purkinje fibres, spreading to contractile cells initiating contraction

28
Q

What are myocardial conducting cells?

A
  • Initiate action potential that travels through heart muscle
  • Triggers contraction that propels blood
29
Q

What are myocardial contractile cells?

A
  • Conduct impulses that pump blood through body connected to each other by intercalated disks
  • Gap junctions allows pacemaker to transfer depolarisation and contract coordinated manner
30
Q

What characteristics of cardiac pacemaker cells make them well suited to stimulating the cardiac muscle to contract?

A

Have automaticity: can generate an action potential without command from the nervous system
Have conductivity: ability to pass action potential to next cardiac cell

31
Q

Describe blood flow in the systemic circuit

A 
Vein (carries blood to the heart)
Venule
Capillary Network 
Arteriole 
Artery (carries blood from the heart)
32
Q

Describe the walls of arteries and veins

A

Tunica externa: external
Tunica media: middle
Tunica intima: internal

33
Q

What are capillaries?

A

Function in a 2 way exchange

  • nutrients and oxygen to tissues
  • waste products and CO2 from tissues
34
Q

Describe the two types of capillaries

A

1) Continuous capillaries
- complete endothelium
- diffusion: prevent loss of blood and plasma proteins
2) Fenestrated capillaries
- pores: faster exchange, larger molecules

35
Q

Describe arterial blood pressure

A
  • Pressure that exerts organs against inner walls of blood vessels
  • Maintains adequate blood flow
  • Blood flow driven by pressure gradient
  • Flows from high to low pressure
36
Q

Describe the process of blood flow

A
  • Ventricles contract
  • Blood forced into elastic arteries
  • High pressure forces blood forward
  • Into areas of lower pressure
37
Q

What is venous pressure?

A

Determines venous return: amount of blood arriving at the renal artery each minute
-Must overcome gravity when standing

38
Q

Describe muscular compression

A

Contractions of skeletal muscle compresses veins, pushing blood flow towards the heart

39
Q

Describe the respiratory pump

A
  • Inhalation decrease pressure in thoracic cavity
  • Draws air in lungs, expands inferior vena cava: draw blood in right atrium
  • Allows filling, improve venous return
40
Q

What are determinants of blood pressure?

A

1) Cardiac Output
2) Blood Volume
3) Resistance

41
Q

Describe influence of cardiac output on blood pressure

A
  • Volume of blood being pumped by heart from left or right ventricle
  • Depends on heart rate and stroke volume
  • Increase cardiac output = increase blood pressure
  • Heart rate and stroke volume increase from sympathetic activity
  • Stroke volume increases venous return; vasoconstriction, skeletal muscle and respiratory pump enhances venous return
42
Q

Describe influence of blood volume on blood pressure

A
  • Influences how much blood is returned to heart
  • Increase BV: Increase CO: Increase BP
  • Depends on side of fluid between capillaries & interstitial spaces in cells
  • Depends on salt/water balance controlled by RAAS system & ADH
43
Q

Describe influence of resistance on blood pressure

A

-Depends on radius of arterioles, blood viscosity, vessel length & blood flow
-Decrease diameter: vasoconstriction
-Increase diameter: vasodilation
HIGH resistance= HIGH blood pressure
LOW resistance= LOW blood pressure
-Arteriole radius determined by intrinsic (metabolic control) and extrinsic (sympathetic activity, hormones: ADH and angiotensin II) factors

44
Q

Why are cardiovascular regulatory mechanisms important for blood flow?

A

Ensures blood flow through tissues meets demands for oxygen and nutrients

45
Q

Describe auto regulation of blood flow

A
  • Local/immediate adjustment
  • Peripheral resistance within individual tissues adjusted
  • Smooth muscle cells in pre-capillary sphincters respond automatically to changes in local environment
46
Q

Describe neural regulation of blood flow

A
  • Involves nervous system
  • Makes short-term adjustments to CO and maintain BP & adequate blood flow
  • Receive input from sensors that detect changes in:
  • arterial blood/BP
  • PH
  • Gas concentration
  • Increase CO= increase BP from sympathetic NS
  • Decrease CO, decrease BP from parasympathetic NS
47
Q

Describe the baroreceptor reflex

A
  • Prevents sudden rise/fall in BP
  • Pressure sensor monitors stretch in wall of vessels
  • Restores homeostasis via negative feedback
48
Q

What is the role of chemoreceptors?

A
  • Short term regulation
  • Responds to changes in chemicals
  • Integrates cardiovascular and and respiratory system
49
Q

Describe role of hormones in the cardiovascular system

A 
SHORT term regulation:
-Adrenaline/noradrenaline
-sympathetic response
LONG term regulation
-alters fluid balance and blood volume with:
*Angiotensin II
*Aldosterone
-ADH
50
Q

Describe renal regulation in the cardiovascular system

A
  • Endocrine response of kidneys to increase BV & BP
  • In response to decreased oxygen
  • EPO release, more RBCs
  • Increased hematocrit: increase BV
  • Increase BP delivers more oxygen to kidneys
  • Renin released to stimulate RAAS pathway

Physiology Essentials (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions